The use of fiber optic means to transport electromagnetic wavelengths is well known. In the area of chemical analysis, for instance, various Patents describe the use of fiber optics to carry electromagnetic wavelengths from a source thereof, to a system in which said electromagnetic wavelengths are caused to interact with a sample analyte. As well, various Patents describe the use of fiber optic means to carry said electromagnetic wavelengths which have interacted with said sample analyte to a detecting means. For instance, a Patent to Zare et al., U.S. Pat. No. 4,675,300 describes a method of detecting laser excited fluorescence in an electrokinetic separation system. Said electrokinetic system involved orients a fiber optic means other than axially with respect to an orientation of a flow containing a sample analyte. It is noted that sample analyte flow is effected in the Zare et al. system by application of an electrical potential between a source of sample analyte containing solution, and an outflow container therefore.
A long path flow cell is described in U.S. Pat. No. 5,140,169 to Evens et al. Said Evens et al. system is described as a metal body containing a circular opening at each end extending perpendicularly into a center bore, adapted to receive a sample into the center bore and discharge sample from said center bore. As well, opposing fiber optic probes, each with an external sapphire window which is sealed into said metal body, are present. In use light is piped into one said fiber optic probe, caused to pass axially through said metal body, and exit via said opposing fiber optic probe. Appropriate analysis of a change effected in said light between entry and exit from said metal body allows sample analyte caused to be present in said metal body to be identified.
Another U.S. Pat. No. 5,096,671 to Kane et al., provides that light carrying optical fibers axially enter light to a system which contains a chemical sensor. Axially oriented exiting optical fibers are also present such that in use entered light is caused to interact with said chemical sensor, and then exit therethrough. Interaction with said chemical sensor effects a change in the light between entry thereto and exit therefrom, and chemicals to which the chemical sensor is sensitive affect the properties of the chemical sensor. Said 671 Patent discloses that the sensor can operate utilizing fluorescence. In use the presence of chemicals to which the chemical sensor is sensitive can then be detected.
Another U.S. Pat. No. 4,837,777 to Jones describes a system which utilizes fiber optics to carry light axially into and out of a chamber in which the pressure or temperature can be altered. Changes in light entered to and exiting from said chamber are related to changes in pressure or temperature in said chamber.
A Patent to Buckles, U.S. Pat. No. 4,399,099 describes a system in which an optical fiber is contained in a system into which a fluid is entered. Said fluid causes change in the optical properties of said optical fiber, and detecting changes of light caused to pass therethrough in use, before and after entry of said fluid, is related to the properties of the entered fluid.
U.S. Pat. No. 4,740,709 to Leighton et al., describes a housing with orifices present therein through which liquid is caused to flow in use. An axially oriented light source and a facing sensor are also present. Said system is utilized in measurement of optical density or light scattering measurements in a turbulently entered liquid.
U.S. Pat. No. 4,682,895 to Costello describes a system in which a fiber optic probe carries light into and out of a system. Present within said system is a sample chamber into which sample is entered during use. Said sample chamber essentially comprises a gap in said fiber optic probe pathway. In use light is entered into one end of said fiber optic probe and the light exiting said fiber optic probe is affected by what sample is placed into said sample chamber. The change in light between entry and exit from said fiber optic probe is identifying of said sample.
U.S. Pat. No. 4,844,869 to Glass describes an immunoassay apparatus which employees total internal reflectance of excitation radiation at the interface between an optically conductive rod or fiber and a surrounding liquid. In use radiation is launched onto an unsupported end of a cantelivered rod or fiber and fluorescence radiation tunneling into the unsupported end of the rod or fiber is observed at the same end of the fiber.
U.S. Pat. No. 5,594,545 to Saito et al. describes microflow cell for application in capillary electrophoresis comprising an outer cylinder disposed on the outer periphery of a cylindrical flow cell, with a filling material present between the outer cylinder and the flow cell.
U.S. Pat. No. 5,068,542, to Ando et al., describes use of a fiber optic to intercept axially provided light produced by a laser system. The fiber optics which carry light to a detector involved are not present inside an axially oriented sample containing tube, however. It is noted that the system in Ando et al. does not provide an open ended tube. Either end caps are present on both ends thereof to support liquid inlet and outlet means, or one end thereof is closed with an optical fiber secured therein and the other end thereof has an end cap thereon.
U.S. Pat. No. 5,068,542 to Ferrari et al. describes a system in which end caps affixed to a tube contain light fibers which both carry light from a source thereof, and to a detector. It is noted that the system in Ferrari et al. does not provide an open ended tube, in that end caps are present on both ends thereof to support present fiber optic means.
Patents which arguably describe modular elements from which project ports are U.S. Pat. No. 5,078,493 to Evens et al.; U.S. Pat. No. 5,151,474 to Lange et al.; U.S. Pat. No. 5,302,272 to Klein and PCT Application No. WO 97/28477. However, none of said references identify use in a sample analyte identifying fluorescence inducing system.
Also, it is noted that two additional U.S. Pat. No. 5,068,542 to Ando et al. and U.S. Pat. No. 3,834,821 to Ferrari et al. describe the presence of optical fibers which extend only a short distance into the effective systems thereof, (ie. into end caps (116) & (114) in Ferrari et al. and into tube (1) of Ando et al. This is beneficial to operation of the both the 542 and 821 Patent Inventions as fluid flow through the respective tubes is not blocked or impeded by optical fibers in use.
Finally, a paper by Yeung et al, titled "Laser Fluorescence Detector For Capillary Electrophoresis", J. Chromatography, 608(1992), 73-77, describes a laser-based fluorometer for use in detection in capillary electrophoresis. While laser induced fluorescence, in combination with electrophoresis mediated provision of sample analyte into the described system is reported to be a very efficient approach to sample analyte identification, the use of axially oriented optical fibers in a system for detection of sample analyte identifying fluorescence is not described.
The above discussion of known Patents and Articles shows that while the use of optical fibers in systems for use in sample analysis is known, no known system or method provides that axially oriented fiber optic means should be present within at least a majority of an axially oriented modular component of a sample analysis system in which sample analyte fluorescence is caused to occur by the application of energy to a present sample analyte. This is particularly true where fluorescence inducing energy is entered along a pathway other than parallel to a longitudinal direction of a system for use in sample analysis, and where sample analyte investigated is caused to enter a modular component of a sample analysis system by electrophoresis. Neither does any known system or method describe use of a system with at least four ports, each of which ports projects from a common volume, two of said ports having the fiber optic means present therein, and two of which provide access to sample analyte containing sample solution. The present invention provides such systems and methods of its use.